Paternity in socially housed primates is often unequal, such that particular males may sire many more offspring than others. Many factors, such as dominance, weight, and female preference have been proposed to account for this difference. In this study, we examined whether or not temperament, as measured by willingness to explore novel items, affected reproductive success in male rhesus macaques (Macaca mulatta). Subjects (n=11) were 10-12 years of age, and housed in one of two 1-acre outdoor corrals at the Oregon National Primate Research Center. Each corral contained approximately 50 adult females, 4-6 adult males and juvenile offspring. We assessed temperament when the animals were brought inside for annual physical exams by presenting them with both a novel food and novel object in their cage. We then compared latency to inspect the objects with the cumulative number of offspring sired, based on paternity records. There was a bimodal distribution in response to the novel objects. While most of the males (“bold”) immediately (< 10s) inspected the objects, a smaller subset (“shy,” n=4) took longer to inspect the objects. The shy monkeys had fewer offspring compared to the more exploratory individuals (p=0.047). There was no difference between temperament and age (p=0.819) or age and number of offspring (p=0.522). Our data suggest that male temperament may be an additional influence on male reproductive success in our corrals.